"People have got on that bus and put their lives in that driver's hands," he said.

"Parents will send their children off to school thinking they're safe. If the driver were to crash, it could have catastrophic consequences, people could be killed.

"It's disgusting that a professional driver could take such drastic risks and risk passengers lives. This is one of my pet hates, I have been a bus driver for 15 years and I know you need absolute 100% concentration at all times."

A spokesperson for TrustyBus, which operates services in Essex and Hertfordshire, said: "We take passenger safety very seriously and an investigation is under way. We can't comment any further due to staff confidentiality."